Trees respond to wounding or injury by forming specialized “callus” tissue around the edges of the wound. Thus, the tree responds to the injury by “compartmentalizing” or isolating the older, injured tissue with the gradual growth of new, healthy tissue. Not only do trees try to close the damaged tissue from the outside, they also make the existing wood surrounding the wound unsuitable for spread of decay organisms. Often a raised area of “callus tissue” will develop in the tree’s attempt to close the wound. However, even a slight opening may be enough to allow insect pests and fungal diseases to infest or infect the tree. When a tree receives a trunk wound that penetrates the cambium layer it can interfere with the movement of water and nutrients. A wound can become a pathway for diseases, insects or decay.

The best defense here is to use good cultural practices to ensure your tree is the healthiest it can be: make sure you water your tree during drought conditions, avoid compacting the soil around it, remove leaf debris in the fall, and amend your soil with organic fertilizers (compost) and mulch (not touching the base of the trunk but in a circle around it).

This type of bark-splitting is often associated with southwest exposure. On bright sunny days the southwest side of the tree heats up, absorbing the heat of the sun. This sun scald results in the death of the exposed bark. The result is a vertical fissure down the center of the tree trunk, causing strips of bark to peel off, exposing the tree’s inner wood. These cracks may cause stress for your tree and provide a point of entry for pests and diseases. Damage from sunscald injury may eventually heal.

When a tree receives a trunk wound that penetrates the cambium layer it can interfere with the Major structural trimming may be done before the new leaves unfurl in spring. Lighter pruning can be accomplished any time in June after the first major flush of growth begins.movement of water and nutrients. A wound can become a pathway for diseases, insects or decay“.

Japanese-maples once established, should be lightly fertilized only in the early spring (April) with 4-12-8 fertilizer or 15-30-15 water soluble mixture. Major structural trimming may be done before the new leaves unfurl in spring. Lighter pruning can be accomplished any time in June after the first major flush of growth begins.